VideoDecodeAccelerator now SupportsWeakPtr instead of being RefCountedThreadSafe.

content/common/gpu/media/omx_video_decode_accelerator.cc

Index: content/common/gpu/media/omx_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/omx_video_decode_accelerator.cc b/content/common/gpu/media/omx_video_decode_accelerator.cc
index 7bcd1bb57fe98a2760d51b0d25730752d8bf32e7..9818626544d185c88a5b0ead702a325181e62c7e 100644
--- a/content/common/gpu/media/omx_video_decode_accelerator.cc
+++ b/content/common/gpu/media/omx_video_decode_accelerator.cc
@@ -190,7 +190,6 @@ bool OmxVideoDecodeAccelerator::CreateComponent() {
                     PLATFORM_FAILURE, false);
 
   // Get the handle to the component.
-  AddRef();  // To reflect passing |this| to OMX_GetHandle below.
   result = omx_gethandle(
       &component_handle_, reinterpret_cast<OMX_STRING>(component.get()),
       this, &omx_accelerator_callbacks);
@@ -437,7 +436,8 @@ void OmxVideoDecodeAccelerator::Reset() {
   BeginTransitionToState(OMX_StatePause);
 }
 
-void OmxVideoDecodeAccelerator::Destroy() {
+void OmxVideoDecodeAccelerator::Destroy(
+    scoped_ptr<VideoDecodeAccelerator> self) {
   DCHECK_EQ(message_loop_, MessageLoop::current());
   if (current_state_change_ == ERRORING ||
       current_state_change_ == DESTROYING) {
@@ -462,7 +462,7 @@ void OmxVideoDecodeAccelerator::Destroy() {
   current_state_change_ = DESTROYING;
   client_ = NULL;
   BeginTransitionToState(OMX_StateIdle);
-  BusyLoopInDestroying();
+  BusyLoopInDestroying(self.Pass());
 }
 
 void OmxVideoDecodeAccelerator::BeginTransitionToState(
@@ -562,14 +562,16 @@ void OmxVideoDecodeAccelerator::OnReachedExecutingInResetting() {
 // outlives the shutdown dance, even during process shutdown.  We do this by
 // repeatedly enqueuing a no-op task until shutdown is complete, since
 // MessageLoop's shutdown drains pending tasks.
-void OmxVideoDecodeAccelerator::BusyLoopInDestroying() {
+void OmxVideoDecodeAccelerator::BusyLoopInDestroying(
+    scoped_ptr<VideoDecodeAccelerator> self) {
   if (!component_handle_) return;
   // Can't use PostDelayedTask here because MessageLoop doesn't drain delayed
   // tasks.  Instead we sleep for 5ms.  Really.
   base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(5));
   message_loop_->PostTask(
       FROM_HERE, base::Bind(
-          &OmxVideoDecodeAccelerator::BusyLoopInDestroying, this));
+          &OmxVideoDecodeAccelerator::BusyLoopInDestroying,
+          base::Unretained(this), base::Passed(&self)));
 }
 
 void OmxVideoDecodeAccelerator::OnReachedIdleInDestroying() {
@@ -590,8 +592,6 @@ void OmxVideoDecodeAccelerator::OnReachedIdleInDestroying() {
     FreeInputBuffers();
   if (!output_buffers_at_component_)
     FreeOutputBuffers();
-
-  BusyLoopInDestroying();
 }
 
 void OmxVideoDecodeAccelerator::OnReachedLoadedInDestroying() {
@@ -610,12 +610,10 @@ void OmxVideoDecodeAccelerator::ShutdownComponent() {
   OMX_ERRORTYPE result = omx_free_handle(component_handle_);
   if (result != OMX_ErrorNone)
     DLOG(ERROR) << "OMX_FreeHandle() error. Error code: " << result;
-  component_handle_ = NULL;
   client_state_ = OMX_StateMax;
-  // This Release() call must happen *after* any access to |*this| because it
-  // might result in |this| being deleted.
-  Release();  // Since OMX no longer has |this| to call back to.
   omx_deinit();
+  // Allow BusyLoopInDestroying to exit and delete |this|.
+  component_handle_ = NULL;
 }
 
 void OmxVideoDecodeAccelerator::StopOnError(
@@ -1000,8 +998,8 @@ OMX_ERRORTYPE OmxVideoDecodeAccelerator::EventHandler(OMX_HANDLETYPE component,
       static_cast<OmxVideoDecodeAccelerator*>(priv_data);
   DCHECK_EQ(component, decoder->component_handle_);
   decoder->message_loop_->PostTask(FROM_HERE, base::Bind(
-      &OmxVideoDecodeAccelerator::EventHandlerCompleteTask, decoder,
-      event, data1, data2));
+      &OmxVideoDecodeAccelerator::EventHandlerCompleteTask,
+      base::AsWeakPtr(decoder), event, data1, data2));
   return OMX_ErrorNone;
 }
 
@@ -1017,7 +1015,8 @@ OMX_ERRORTYPE OmxVideoDecodeAccelerator::EmptyBufferCallback(
       static_cast<OmxVideoDecodeAccelerator*>(priv_data);
   DCHECK_EQ(component, decoder->component_handle_);
   decoder->message_loop_->PostTask(FROM_HERE, base::Bind(
-      &OmxVideoDecodeAccelerator::EmptyBufferDoneTask, decoder, buffer));
+      &OmxVideoDecodeAccelerator::EmptyBufferDoneTask, base::AsWeakPtr(decoder),
+      buffer));
   return OMX_ErrorNone;
 }
 
@@ -1037,7 +1036,8 @@ OMX_ERRORTYPE OmxVideoDecodeAccelerator::FillBufferCallback(
       static_cast<OmxVideoDecodeAccelerator*>(priv_data);
   DCHECK_EQ(component, decoder->component_handle_);
   decoder->message_loop_->PostTask(FROM_HERE, base::Bind(
-      &OmxVideoDecodeAccelerator::FillBufferDoneTask, decoder, buffer));
+      &OmxVideoDecodeAccelerator::FillBufferDoneTask, base::AsWeakPtr(decoder),
+      buffer));
   return OMX_ErrorNone;
 }